Runners competing in triathlons face difficulty in preparing for racing because of a lack of effective training options for the cycling portions of a race when outdoor cycling is unavailable or undesirable. Various exercise bicycles simulate natural or outdoor cycling with varying degrees of success, but since a triathlete competes on his own bicycle and not the exercise equipment, stationary bike training is less effective in developing the muscle groups, balance, posture, and other elements that can impact the competitor's efficiency and comfort while riding his own bicycle.
Various systems have been devised to allow cyclists to ride on an endless tread belt, but all have come with significant limitations. One such system is disclosed in U.S. Pat. No. 7,220,219 to Papadopoulos. In this reference, a treadmill assembly includes a frame and a treadmill belt. In addition, a sensor produces a signal representative of an aspect of the user's position relative to at least one point on the frame. A belt rotation assembly turns the belt with a speed related to the signal. In one preferred embodiment the speed of the belt is inversely proportional to the distance between the user and the front of the treadmill. In another preferred embodiment the treadmill is sized to support a cycle. Other systems are disclosed in U.S. Pat. No. 7,618,353 to Papadopoulos; U.S. Pat. No. 4,925,183 to Charles F. Lind, and U.S. Pat. No. 5,743,835 to Edward E. Trotter. Each of these references are herein incorporated by reference for all that they contain.